The automatic transmission is an apparatus used in motor vehicles. Its purpose is to transmit power from the internal combustion engine to the wheels. The 722.6 is Mercedes Benz's five speed automatic transmission while the 722.9 is Mercedes Benz's seven speed automatic transmission.
In the 722.6 and 722.9 automatic transmissions, there is a set of two steel pump gears that rotate and are responsible for hydraulic pressure for transmission operation. These two pump gears often break. When they break, they cause damage to the surface area of an aluminum or magnesium bellhousing on which they rotate.
A prior art supposedly protects a good bellhousing from being damaged. However, because it is inherently weaker in construction, the prior art is not to be used for damaged bellhousings. Furthermore, the prior art does not completely support both rotating pump gears.
Additionally, the prior art does not completely enclose both pump gears within a pump gear housing to ensure no further damage is possible to a bellhousing.
For example, FIG. 1 shows a prior art 24 design. The prior art has a thin rim 26 on which the inner pump gear 20 rotates. FIG. 3 shows a larger view of the thin rim 26. Additionally, the prior art 24 lacks total outer gear support and containment as is shown by the gaps 28 that are circled.
As a result, FIG. 1, FIG. 3 and FIG. 7 shows the prior art as being a weaker design.